Pavement



Feb. 28, 1928.

H. M. KNIGHT PAVEMENT Filed Aug. 10. 1921 2 Sheets-Sheet 1 Feb. 28,1928.

1,660,421 H. M. KNIGHT PAVEMENT Filed Aug. 10. 1921 2 Sheets-Sheet 2Patented Feb. 28, 1928.

UNITED STATES PATENT vr f s HERBERT M. KNIG T; or mountain, JERSEY.

rav'nivrnn'r.

Application filed August 10,1921. Serial No. 491,227.

This invention relates to pavements, and has special reference topavements composed in part of pre-cast concrete units.

One of the objects of the invention is to provide a pavement built up ofunits, any,

one or several ofwhich may subsequently be removed and replaced. Anotherob ect of the invention is to provide apavement, parts of which may beremoved for the purpose of permitting underground work to be performed,while the remainder of the pavement ren'iains intact, permitting ofcontinuous use by tratlic. Another object of theinvention is-to provideapavement built up of precast 1 a pavement built up of pike-castunitswith means for filling void spaces which may exist beneath saidpavement. Another object of the invention is to provide a pavement, oneportion of which consists of pre-cast slabs resting upon and removablyattached to sills supporting said slabs. A further object of theinvention is to produce a unit type of pavement in which the severalunits composing similar parts shall be interchangeable. Still anotherobject of the invention is to provide a pavement with ducts therein forthe passage of heat for the melting of ice and snow from the surfaceoflthe said pavement. Another object of the invention to provide apavement, the pre-cast slabs of which are supported inpart by thecurbing along said pavement. Other ob ects of the nventuim will appearfrom the followingdescription and from the aiamnmanying drawings.

The accompanying drawings, Figures 1 to 13 inclusive, are illustrativeof the invention, and indicate the usual and preferred embodimentthereof. They are however illustrative only and are not to be consideredas inclusive of all types in which the invention may be a slab or unitemployed in the said pave Inent; Fig. 4 is a section at the curb-lineand shoulders 3 and 5.

Fig. 5 .a'section at an intermediate-sill; Fig.

6 is an elevation ofthe hook-bolt used for removablyconnecting the slabsto the curbs and sills; Fig. 7 is a section ofsuch a hook bolt on theline 7- 7 of Fig. 6; Fig. 8 is a section of the bolt on the line8.8 ofFig. (3 Fig. 9 is a plan of a portion of a pavement at a sill with thewearing coat removed; Fig. 10 IS a plan view of a curb; Fig. 1l is anelevation of a sill and Fig. 12 a plan-view of such asill. Fig. 13is.a'cross-sectionof a sill and pavement showingtheir application in thesupport and maintenance of a rail.

Referringto the drawings inwhichsimilar figures refer to similar parts.-1 is a precast slab partially supported by a curb 2 hav-,

mg a shoulder 3 positioned to support said slab. "lhe slab may also besupported in whole or in part by a sill 4 having a shoulder a at theupper part thereof.

Hook-bolts ('3 pass through bolt holes 7 in sa d slab, said boltsremovablyengagingsa d shoulders 3 and 5. The bolt holes 7 have anelongated opening 8 in the bottom face oft-he slab and are providedwitha shoulderQ for the purpose of engaging a washer 1O which is forcedagainst the shoulder 9 by a nut 11 which engages a screw thread on theshank of the hook-bolt. The hook-boltG has an extension 13. with anupper face l l flattened to make superficial contact with the-bottoinofthe A hole 15 for the purpose of washing or grouting material be-..

neath the pavement after the placing ofthe slabs and before'the layingof the wearing coat, and also as a. means of handling the v slabs duringthe processof insertion or re ing bolts and removing and handling slabs.A wearing coat 17 covers the slabs and fills the joints between theseveral slabs and between the slabs and curbs.

body of the slabs, th e ducts of juxtaposed slabs being in linearalinement. A boss 19 is formed upon the bottom of the sill 4 and rebates20 on the inner faces thereof. Bolt holes 21 pass through the webs ofthe sills and bolts 22 are insertedin said bolt holes and securelyfasten the duplicate parts of the sills together. Clips 23. are shown,positioned in the rebates 20 having bolt holes 24 Ducts 18 for the Ipurposeof conveying heat, are formed in the therein through which thebolts 22 pass. The upper ends of said clips 23 are provided with anoffset 25 adapted to engage the base of a rail 26 andvto be securedthereto by means of a wedge 27. The upper flange of the sill 4 has adepression 28 adapted to re ceive the base of the rail 26, and a chase29 adapted to receive the offset 25 ofthe clip 23. The chase 29 has anoblique back 30 permitting latitude of movement of theclip .23. Ashoulder 31 is formed uponthe back ofthe curb 2, snpportingthe sidewalkslab 32. Sewers 33, conduits 34, water pipes 36 and gas pipes 37 areindicated as located beneath the said pavement.

In the constructmn of city pavements, as

usually performed, a foundation of concrete 71s laid upon the sub-grade,either with or without consolidation, and a wearing. coat of brick,asphalt, or other resistant or re- 7 silient material is superimposedthereupon. Subsequently excavations are made through this foundation andwearing material, 111

order to reach and repair existing sub-sun I face pipes, or for thepurpose of introducing new ones. In the process of such excavation allof the foundation and other pave-' ment material removed is broken upand destroyed, and an area largely in excess of that required-isinjured, such destruction and injuryentailing great waste and heavycosts for restoration. In the pavement herein illustrated, pre-castslabs, usually of concrete, are supported upon curbs and 1011-'gitudinal sills and .removably attachedto said curbs and sills by meansof hookbolts, which, while holding the slabs rigidly iii position whilethe pavement is in service, are quickly and easily removable, allowingthe slab,-with its superimposed wearing surface to be removed from thesection of the roadway, beneath which it is desired to make excavation.All of the removed paving material, being by this process preserved, iseasily and quickly returned to position and the pavement immediatelyrestored. The only portions of the wearing surface destroyed aretheportions along the cdgesof the slabs, therestoration of which is a smalland inexpensive matter. The hook-bolt being of the illustrated form iseasily inserted in the bolt hole through the slab, the elongated bottomof the said bolt hole permitting of the introduction of the hook-bolt sothat the hook is parallel to the curb or sill, when, upon suchintroduction, the hook is turned through an angle of 90 degrees and theflattened face of the hook brought into contact with the lower face ofthe shoulder on the curb or sill and fas-' tened thereto by means of thenut resting upon the washer which is in contact with the shoulder withinthe bolt hole. As the bolt hole is filled with some easily removablematerial which is easily removable and a above freezing.

with the major axis ofthe elongated aper-y ture and withdrawing it fromthe pavement.

The slabs are thereupon freed from the sills or curbs-and can be lifted,andsuhsequently replaced, it being possible to rc-insert and fasten thesame bolts in the same as the initial manner.

ment is the possibility of cavitiesbeing left,

One of the defects of a slab type of paveor later appearing, beneath thepavementlVhile a sub-grade can be so carefully dressed as to make thepresence of such "cavities both small. or remote, provision againsttheir arising and becoming a dangerous menace to the life or safety ofthe pavement are desirable. For the purpose of preventing the presenceof such cavities. after the pavement shall have been laid or 'replaced,

grouting holes are provided in each of the slabs or units making up thepavementy through which earth or other material may be washed or groutedbeneath the slabs, in

advance of the laying of the wearing coa:t.

By such washing or groutingall voids beneath thepavement are filled, anda'pave ment resting firmly upon the soilover its entire area is secured.

The slabs rest upon curbs and also upon loo longitudinal sills, thelatter, for greater ease in manufacture and in handling, being inmultiple, the said multiple sill units being assembled in relativelyreversed position in the pavement and breaking joint with each other.They are connected together by bolts. Such multipliclty of members andsuch breaking of jointsproduces a rigid struc ture and preventsirregular settlement vof the pavement under traffic. The superficialpie-cast slabs supported by the curbs and sills, likewise are staggeredso as to give a maximum ofstrength and to insure a regularity ofsurface. The sills are rebated, on their backs, the purpose of suchrebating in} ing to provide a slot or space for the in sertion of means,such as the tie .or clip shown, for fastening a rail, or othersuperficial bodyor construction, to the sills or V pavement. V y a i lthe greatestdrawbacks to the use One of of a smooth pavement incitvstreets, where frost conditions are liable to exist, in the coldermonths, is the formation of a thin coating of ice thereon, making thepavement very slippery and dangerous to either hon-ire drawn or motortraffic. Such slipper-i,- ncsscan be prevented if the surface of thepavement is maintained at a degree ortwo Again, except for excessivelyheavy snowfalls, the removal of the snow can be greatly facilitated,ifnotene tirely performed, if the pavement is kept slightly .warm,sufiiciently to melt the snow as it falls. '13 or the purpose ofsecuring this result, ducts are shownas havingbeen formed in the body ofthe slabs during the casting thereof, so alined as to make a coninuouspassage ,orv series ofipassages, under.

and through the pavement, such ducts lead mg to some central heatingplant, from which hot a r, steam or hot water is ClICUr lated for thepurpose of heating the pave-I meut to a temperature slightly abovefreezing.

The wearing surface, being laid in situ, and after the slabs have beenattached to the curbs and SlllS, fills all cracks and other divisionallines betweenthe slabs and be. tween the slabs and curbs, and makesthere units and bolts engaging under said shoul ders on said sills andremovably attaching said slabs and said sills.

2. In a pavement, a pre-cast slab, a sill supporting said slab, saidsill being composed of a multiple of units having rebated backs,downwardly facing shoulders on the upper portion of said unitsoppositely disposed to said rebated backs, flanges on the lower portionof said units, fastening means joining said units and bolts passingthrough boltholes in said slabs and engagingunder said shoulders on saidsills and removably attaching said slabs and said sills.

3. In a pavement,- a pro-cast slab,sills supporting said slab, saidsills being composed of a multiple of units, shoulders on the upperportion of said units, flanges on the lower portion of said units,fastening means joining said units, bolts engaging said shoulders onsaid sills and removably attaching said slabs and said sills and asuperficial wearing coat upon said slabs.

l. In a pavement, a pre-cast slab, sills supporting said slab, saidsills being composed of a multiple of units, rebated backs to saidunits, shoulders on theupper portion of said units oppositely disposedto said rebated backs, flanges on the lower portion of said units,fastening means joining said units, bolts passing through bolt-holes insaid slabs and engaging said shoulders on said sills and removablyattaching said slabs and said sills and a superficial wearing coat uponsaid slabs. f

5. In a pavement, a pre-cast slab, sills supporting said slab, saidsills being composed of a multiple of units, downwardly direct edshoulders on the upper portionof said uni.ts,ifia nges on the lowerportionof said un1ts,wfasten1ng means oining saidunits,

bolts engaging under said shoulders on said slabs. engaging saidshoulders on said sills and removably attaching saidslabs and said sillsand groutingholes in said slabs.

7. In a pavement, pre-cast slabs, a plural ity of sills common to aplurality'of slabs and supporting the same, said sills being composed ofa multiple of units, shoulders on the upper portion of said units,flanges on the lower portion of said units, fastening means joining saidunits, bolts engagingsaid shoulders on said $1115 and removablyattaching said slabs and said sills, and ducts in said slabs, said ductsbeing alined in successive slabs and held in alinement by the attachingof said slabs to the common sills.

8. In a pavement, a plurality of juxtaposed alined pre-cast -slabs,'aplurality of sills common to a plurality of slabs and interposed underthe marginal alined edges of portion of said units, flanges on the lowerportion of said units, fastening means joining said units, boltsengaging said shoulders on said sills and removably attaching said slabsand said sills and ducts in said slabs,

said ducts in juxtaposed slab being in linear alinement, and held inalinement by the attaching of said slabs at their alined edges to thecommon sills.

9. In a pavement, a pre-cast slab, sills supporting said slab, saidsills being composed of a multiple of units, rebated backs to saidunits, shoulders on'the upper portion of said units 0 positely disposedto said rebated backs, units, fastening means joining said units,

bolts passing through bolt-holes in said slabs anges on the lowerportion of said cast slabs, precast curbs and sills support? ing saidslabs, bolts passing through boltholes in said slabs and engagingshoulders on said pro-cast curbs and sills and removabl-y attaching saidslabs 'to said curbs and sills, grouting holes i-nsaid slabs, ducts insaid slabs and a wearing coat superimposed upon said slabs. l i i 12. Ina pavement, a multiple of precast slabs, a hook-boltand a projecting armto said bolt, the upper surface of which arm is flattened.

13. In a pavement,

'. the combinati on of pro-cast slabs, pro-cast curbs and ,pre-eastsills supporting said slabs,,ho0k-bolts passing through shoulderedbolt-holes having an elongated louver aperture, in said slabs, andengaging shoulders onsaid pro-cast curbs and prc=cast-sills,andrcmorably attaching.

said slabsxto said curbs and sills, grouting liolesin said slabs, ductsin said slabs and a wearing coat superim oed upon said slabs.

Signed at- New Yor in the county of New Yo-rk and State of New York thisninthday of August, A. V HERBERT M. KNIGHT;

